I know the compensating sprocket powers the primary chain and clutch but what is the function of the sliding cam and why is it called the compensating sprocket, ie, what is compenstated? Thanks v

 

The driveline is compensated for power pulses of the engine,due to uneven firing order.

 

I don't know why it is called a compensator, that has never made sense to me. It is a transmission shock absorber and was commonly fitted on many brands of bike way back, such as most British bikes, in my experience. When each cylinder fires it accelerates the crankshaft quickly and the compensator cushions some of that thrust. The crankshaft slows down a little, then the next cylinder does the same. The compensator takes the sting out of each cylinder firing. While you're riding along, enjoying a smooth flow of torque at low engine speeds, your crankshaft is giving your poor compensator a lot of work to do!